The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XLII-3, 2018 ISPRS TC III Mid-term Symposium “Developments, Technologies and Applications in Remote Sensing”, 7–10 May, Beijing, China SPATIO-TEMPORAL ASSESSMENT OF MARGALLA HILLS FOREST BY USING LANDSAT IMAGERY FOR YEAR 2000 AND 2018 Rida Batool and Kanwal Javaid The University of the Punjab Quaid-E-Azam Campus Lahore, Pakistan – (rida.xehra93, knwl.j92)@gmail.com KEY WORDS: Change Detection, LULC, Supervised Classification, Satellite Remote Sensing, LANDSAT ETM+ and OLI. ABSTRACT: Environmental imbalance due to human activities has shown serious threat to ecosystem and produced negative impacts. The main goal of this study is to identify, monitor and classify temporal changes of forest cover, build up and open spaces in Margalla Hills National Park, Islamabad. Geographic Information Sciences (GISc) and Remote Sensing (RS) techniques has been used for the assessment of analysis. LANDSAT-7 Enhanced Thematic Mapper (ETM+) and LANDSAT-8 Operational Land Imager (OLI) were utilized for obtaining data of year 2000 and 2018. Temporal changes were evaluated after applying supervised classification and discrimination was analyzed by Per-Pixel based change detection. Results depicts forest cover decrease from 87% to 74% whereas build up has increased from 5% to 7% over the span. Consequences also justify the presence of open land in study area that has been increased from 2% to 7% respectively. 1 INTRODUCTION Classification (Maximum Likelihood) classifies land cover into different classes that comprehends changes and unravel difference In South Asia, Pakistan is among those countries which has very (Walter, 2004). LULC detection with supervised classification is low biodiversity. It has experienced high rates of deforestation considered as the easiest, less time consuming and inexpensive way in recent years (World Resource Institute, 1996). Pakistan to determine dynamics of land rather surveys and labor. covers less than 5% of forest area. One of the major reason of losing forest cover is due to increase in population day by day In this paper method of ‘Per-Pixel Based Change Detection’ has been used to understand maximum to minimum change over 18 that has transformed forested area into agricultural land and for years of study. Pixel as the fundamental unit of image analysis has built-up purposes. A serious notice has been taken by the spectral significance. This method elaborates, pixels of same Government of Pakistan in recent years over deforestation for Digital Number (DN) reflects similar reflectance from ground, significant growth of national parks in different parts of country detects and measure changes on the bases of pixels rather spatial to conserve biodiversity in their natural habitats. There are many content (Hussain et al., 2013). After the detection statistical national parks, reserves and wildlife refuges in Pakistan but the evaluation of each pixel is done by using technique of ‘Image problem is of poor management due to insufficient government Difference’ in GIS. This is an additional way of analysis for funds and poor policies with an open access to the visitors. detecting change of a particular area of interest. Multi-temporal images of different years (2000 and 2018) were subtracted pixel by In Pakistan, there are more than 230 Protected Areas (PAs) which pixel to get appropriate results of changes in Margalla Hills. cover almost 11% (2,753,357 hectares) of the country’s land. These PAs represent almost every ecological, terrestrial and aquatic 2 STUDY AREA ecosystem and are considerably important for their ecological and socio-economic services. The Margalla Hills National Park The study area of this research is Margalla Hills National Park (MHNP) was declared National Park under the Islamabad wild life (MHNP) as depicted by Figure 1. MHNP is located in ordinance (1979) and established in 1980 (Zafar, 2014). Being Islamabad North Pakistan. Its geographical coordinates are capital of country Islamabad is extensively growing and expanding. 33°40′43″N latitude, 72°45′01″ to 72°52′32″E longitude (Zafar, Roads and buildings are developing and ultimately land use land 2014). Hills of Margalla are strechted from north to north-west cover of the city has been changed and will continue to multiply for around 40 km in length (Malik & Hussain, 2003). Margalla coming years (Rai et al., 2011). Hills along with its rugged, gullies and steepe slopes topography is enriched with chemicals like limestone that is also being Many past researchers analyzed various methods for the control detoriate by human activites (Iqbal et al., 2013). and reduction of rapid urbanization within green areas. Though, in this era of modernization assessment and monitoring of land use land cover pattern probe techniques of satellite remote sensing (SRS) and geographic information systems (GIS) globally. Remote Sensing (RS) has provided the opportunity to achieve data and information over the land surface with the help of sensors incorporated with space borne or airborne crafts. These sensors helps to explore earth surface with desired area and specific details. Whereas, GIS helps in mapping those information with their spatial registration and integration of data takes places with both spatial and non-spatial formats for various purposes of vegetation monitoring, identification and classification (Jeyaseelan, 2003). This research study, land use change dynamics were investigated by the combined technological advancements of SRS and GIS. The Figure 1: Study Area Margalla Hills National Park (MHNP) Multi-spectral and temporal classification that is Supervised Islamabad, Pakistan. This contribution has been peer-reviewed. https://doi.org/10.5194/isprs-archives-XLII-3-69-2018 | © Authors 2018. CC BY 4.0 License. 69 The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XLII-3, 2018 ISPRS TC III Mid-term Symposium “Developments, Technologies and Applications in Remote Sensing”, 7–10 May, Beijing, China 3 LAND USE LAND COVER (LULC) Land use and land cover has a unique relationship on both regional and global scale. Human activities like agricultural, cultivation, grazing animals, settlements, developing roads and building infrastructures are categorized as land use while on the other hand environment, biodiversity, natural cover and ecosystems collectively shared by land cover (Turner et al., 1996). In RS, image classification is a science that can transform satellite data into meaning full information that explains about land cover and its condition with class of severity. Purpose of image classification is to categorize, interpret and simplification of data (Zhou et al., 2009). In collaboration with SRS, GIS mapping plays very significant role in the identificaton and analysis of LULC in Margalla Hills. It reveals behaviour of natural resource environment and risk degradation. Figure 2: Land Use/ Land Cover Supervised Classification Margalla Hills National Park (MHNP) Year 2000 Islamabad, 3.1 Supervised Classification (Year 2000) Pakistan. Supervised classification is a type of classification in which numerical discriminators are made up of those data sets already 3.2 Supervised Classification (Year 2018) assigned as a class of their identity for easy identification of For the approximation of LULC for year 2018 similar five larger land covers on land. In this classification, training sites classes were selected as Forest, Open Land, Water bodies, Build are very significant in identification of pixels inside and outside up and shadow. Supervised classification (Maximum Likelihood) training areas before the allocation of classes (Zhou & Wang, was applied on LANDSAT-8 OLI image for year 2018 (6th 2011). Supervised classification is always considered better January) as demonstrated in Figure 3. than supervised because user is already known with the knowledge of what to classify. The temporal analysis with comparison to year 2000 analysis were quite different and changed. As elaborated from Graph 2 For the estimation of LULC year 2000 five classes were classified forested area covers around 496.4897 sq km area in year 2000 as Forest, Open Land, Water bodies, Build up and shadow. has been reduced to 4313.416 sq km or in other words, Supervised classification (Maximum Likelihood) was applied on th percentage of forested area has been lessen to 74% from 87%. LANDSAT-7 ETM+ image for year 2000 (7 January) as presented Similarly, build-up area has increased its ratio from 5% to 7%. in Figure 2. The analysis exhibit forested area is largest that covers Open land has also directed an increasing pattern in Margalla around 496.4897 sq km area and carries almost 87% of total Hills with the area of 56.2676 sq km in current year, the value Margalla Hills also displayed in Graph 1. Build up shows the has been raised from 2% to 7% in previous18 years. Water body second largest area of 40.276 sq km with 5% of total Margalla Hills, has materialized environmental condition during the performance Open land shares third category with area of 17.2192 sq km of 2% of land use land cover classification for year 2018. total while Water bodies shares area of 3.4777 sq km and 1% of total as least area of Margalla Hills. In Figure 3 as compared to figure 2 estimates increased amount of water because of the weather condition of Islamabad. At that time of data acquisition fog and condensation were experienced in study area. Water has not changed its originality from last 18 years but analysis shows the presence of weather factor affecting Build Up Water water area. Open Land 5% 1% 2% Forest 87% Build Up Water 7% 2% Open Land 7% Graph 1: Supervised Classification Area Percentage (%) Margalla Hills Year 2000. Forest 74% Summing up, the LULC classification reports forest area are vast in Margalla Hills and smallest cover is of water bodies in year 2000. Environmental conditions under which the Graph 2: Supervised Classification Area Percentage (%) supervised classification was performed was calm and free of Margalla Hills Year 2018.